1. Field of the Invention
The present invention relates to an interchangeably manual or automatic ratchet wrench tool that may easily change its operative modes, such as a manual operation or an electric operation.
2. Description of the Prior Arts
Referring to FIG. 1, a conventional automatic wrench tool includes a stem 20 disposed at one end of a handle 10, at front end thereof mounted a ratchet seat 21, and in the handle 10 defined a motor driven by a power source for driving the elements in the ratchet seat 21 to move. Referring to FIG. 2, a receiving chamber 210 arranged in the middle of the ratchet seat 21 so as to form first and second retaining circles 211 and 212 at two sides thereof. The first retaining circle 211 is provided with a first bore 213 therethrough, yet the second retaining circle 212 is defined with a second bore 214 therethrough. A rotary shank 22, one end of which is coupled to the motor, and another end of which is fixed an eccentric shaft 221, is used for actuating a driving member 222 to rotate. A rotating block 23 is secured a cavity 231 and inner teeth 232 therearound, the cavity 231 is used to receive the driving member 222 so that the eccentric shaft 221 urges the rotating block 23 to cause a reciprocating rotation during the rotation of the rotary shank 22. A control member 24 is provided at one end thereof with an actuation bar 241, and at another end thereof with a direction switch 242 which serves to control the engaging direction of an arresting member 243 and the inner teeth 232 of the rotating block 23 so that the wrench tool can be alternatively rotated in a clockwise or an anticlockwise direction. A spring pad 25 is fitted to the upper end of the control member 24 having the direction switch 242 thereon, and the control member 24 is inserted through the first bore 213 of the first retaining circle 211. The actuation bar 241 is provided at one end thereof with a washer 26, and a C-shaped retainer 27, by which the actuation bar 241 is defined, is retained in a recess 215 around the second bore 214 such that the conventional automatic wrench tool 10 can be assembled. As shown in FIG. 3, while the rotating block 23 is urged to rotate in a clockwise direction by the rotary shank 22, the actuation bar 241 of the control member 24 is driven to rotate because of the engagement of the arresting member 243 and the inner teeth 232, yet as the rotating block 23 idly rotates in an anticlockwise direction, the inner teeth 232 pushes the arresting member 243 to move inwardly, thus having an idle rotation in the anticlockwise direction so as to operate the automatic wrench tool in a clockwise direction repeatedly. It is to be noted that as the idle rotation of the rotating block 23 in an anticlockwise direction, the control member 24 has to be fixed, or a clockwise direction rotation of the rotating block 23 will cause, hence the fastening or unfastening of the workpiece can not be obtained. Because the friction of the spring pad 25 against the inner wall 216 of the first retaining circle 211 and the C-shaped retainer 27 is utilized to fix the control member 24, while the rotating block 23 rotates in an anticlockwise direction, it tightly engages with the arresting member 243, thus the friction is easily overcome so as to urge the actuation bar 241 to rotate. It can be concluded that the friction is an essential factor, but can not interfere the clockwise rotation of the rotating block 23.
Nevertheless, such a conventional automatic wrench tool still has the following defects that could be improved:
1. As the rotary shank 22 driven by the motor urges the eccentric shaft 221 to actuate the repeated swinging of the rotating block 23 in clockwise and anticlockwise directions, by using the engagement of the arresting member 243 and the inner teeth 232, the control member 24 is alternatively driven to move in an engagable actuating and an idle rotatory returning manner, accordingly such an idle rotary returning results in a wastage of the motor power.
2. The motor is easily controlled to cause clockwise and anticlockwise rotations so that the control member 24 is switched to move in different directions, while such a conventional automatic wrench tool applies the direction switch 242 and the arresting member 243 and cooperates with the retaining effect of the inner teeth 232 to achieve the direction-switching purpose, thus a switch complication will happen.
3. The automatic wrench tool is only driven by the motor, so if the shortage of the motor power occurs, it is not allowed to be operated.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.